GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2008 🢒 Sierra - 4WD 🢒 Engine 🢒 Engine Mechanical - 4.3L 🢒 Upper Intake Manifold Replacement

Removal Procedure

    Object Number: 1878341 Size: SH
  1. Remove the fuel pipes/hoses. Refer to Fuel Hose/Pipes Replacement - Engine Compartment .
  2. Disconnect the following electrical connectors:
    3. • The A/C pressure switch (1), if equipped
    • The air conditioning (A/C) compressor clutch (2), if equipped

    Object Number: 1878388 Size: SH
  3. Disconnect the control port injector module (1).

    4. Object Number: 1876870 Size: SH
  4. Remove the engine wiring harness clips (1, 2) from the engine harness brackets.

    5. Object Number: 1876871 Size: SH
  5. Remove the engine wiring harness rear bracket bolts and bracket.

    6. Object Number: 1876492 Size: SH
  6. Disconnect the following electrical connectors:
    7. • The evaporative emission (EVAP) canister purge solenoid valve (1)
    • The manifold absolute pressure (MAP) sensor

    Object Number: 1876612 Size: SH
  7. Disconnect the evaporative emission (EVAP) canister purge solenoid valve tube quick connect fitting (1) from the EVAP purge solenoid valve. Refer to Plastic Collar Quick Connect Fitting Service .
  8. Reposition the tube out of the way.

    9. Object Number: 1878506 Size: SH
  9. Remove the engine wiring harness ground nut and ground wire (1) from the rear of the right cylinder head.

    10. Object Number: 1878512 Size: SH
  10. Remove the stud (1) holding the engine wiring harness bracket.
  11. Reposition the engine wiring harness with the bracket aside.

    12. Object Number: 869710 Size: SH
  12. Remove the positive crankcase ventilation (PCV) valve hose from the valve and rocker cover.
  13. Disconnect the power brake booster vacuum hose from the vacuum fitting.

    14. Object Number: 516794 Size: SH
  14. Remove the intake manifold - upper studs.
  15. Remove the front 2 throttle body studs.
  16. Remove the intake manifold - upper.

    17. Object Number: 516790 Size: SH
  17. Remove and discard the intake manifold - upper gasket.

    18. Object Number: 516773 Size: SH
  18. Remove and discard the O-ring seal from the fuel meter body.

    19. Object Number: 516797 Size: SH
  19. If required, remove the power brake booster vacuum fitting.
  20. Remove and discard the O-ring seal.

    21. Object Number: 869707 Size: SH
  21. If required, remove the PCV valve cover.
  22. Remove and discard the O-ring seal.

    23. Object Number: 12853 Size: SH
  23. If required, remove the rear throttle body stud.
  24. Remove the throttle body.
  25. Remove and discard the throttle body gasket.

    26. Object Number: 480562 Size: SH
  26. If required, remove the MAP sensor.
  27. Remove and discard the MAP sensor seal.

    28. Object Number: 1503010 Size: SH
  28. If required, remove the EVAP canister purge solenoid valve studs.
  29. Remove the purge solenoid valve.
  30. Clean and inspect the intake manifold - upper, if necessary. Refer to Intake Manifold Cleaning and Inspection .

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1503010 Size: SH
  1. If required, install the purge solenoid valve.
  2. Install the EVAP canister purge solenoid valve studs. If reusing the old studs, apply threadlock to the threads. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.

    3. Tighten
    Tighten the studs to 10 N·m (89 lb in).


    Object Number: 480562 Size: SH
  3. If required, install a NEW MAP sensor seal. Apply a small drop of clean engine oil to the seal.
  4. Install the MAP sensor.

    5. Object Number: 12853 Size: SH
  5. If required, install a NEW throttle body gasket.
  6. Install the throttle body.
  7. Install the rear throttle body stud. If reusing the old stud, apply threadlock to the threads. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.

    8. Tighten
    Tighten the stud to 9 N·m (80 lb in).


    Object Number: 869707 Size: SH
  8. If required, install a NEW O-ring seal to the PCV cover. Apply clean engine oil to the seal.
  9. Install the PCV valve cover.

    10. Object Number: 516797 Size: SH
  10. If required, install a NEW O-ring seal. Apply clean engine oil to the seal.
  11. Install the power brake booster vacuum fitting.

    12. Object Number: 516773 Size: SH
  12. Install a NEW O-ring seal to the fuel meter body.

    13. Object Number: 516790 Size: SH
  13. Install a NEW upper intake manifold gasket.

    14. Object Number: 516794 Size: SH
  14. Install the intake manifold - upper.
  15. If reusing the old throttle body/intake manifold studs, apply threadlock to the threads. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.
  16. Install the front two throttle body studs.
  17. Install the intake manifold - upper studs.

    18. Tighten
    Tighten the studs to 9 N·m (80 lb in).

  18. Connect the power brake booster vacuum hose to the vacuum fitting.

    19. Object Number: 869710 Size: SH
  19. Install the PCV valve hose to the valve cover and rocker cover.

    20. Object Number: 1878512 Size: SH
  20. Position the engine wiring harness and bracket.
  21. Install the engine wiring harness bracket stud (1).

    22. Tighten
    Tighten the stud to 25 N·m (18 lb ft).

  22. Install the engine wiring harness rear bracket nut at the EVAP canister purge solenoid valve.

    23. Tighten
    Tighten the nut to 9 N·m (80 lb in).


    Object Number: 1878506 Size: SH
  23. Install the engine wiring harness ground nut and ground wire (1) to the rear of the right cylinder head.

    24. Tighten
    Tighten the nut to 16 N·m (12 lb ft).


    Object Number: 1876612 Size: SH
  24. Position the EVAP canister purge solenoid tube, and connect the tube quick connect fitting (1) to the EVAP purge solenoid valve. Refer to Plastic Collar Quick Connect Fitting Service .

    25. Object Number: 1876492 Size: SH
  25. Connect the following electrical connectors:
    26. • The EVAP canister purge solenoid valve (1)
    • The MAP sensor

    Object Number: 1876871 Size: SH
  26. Place the engine wiring harness rear bracket onto the upper intake manifold and install the bolts.

    27. Tighten
    Tighten the bolts to 10 N·m (89 lb in).


    Object Number: 1876870 Size: SH
  27. Install the engine wiring harness clips (1, 2) to the engine harness brackets.

    28. Object Number: 1878388 Size: SH
  28. Connect the control port injector module (1).

    29. Object Number: 1878341 Size: SH
  29. Connect the following electrical connectors:
    30. • The A/C compressor clutch (2), if equipped
    • The A/C pressure switch (1), if equipped
  30. Install the fuel pipes/hoses. Refer to Fuel Hose/Pipes Replacement - Engine Compartment .